On dried rims Presta (valve hole diameter: 6.5 mm): depending on the shape of the circle, the flat base of the rubber valve could guarantee a perfect air seal, without any additional adapter, or the conical adapter may be necessary; With an incredible variety of circle profiles on the market, in some cases a flat -based tubeless valve works better than a conical valve and vice versa. In the Mariposa Effect valves, the conical adapter allows you to switch from plan to conical in a moment. We ensure maximum seriousness, we want to receive only positive feedback, therefore, for any problem we are always available, just contact us or with a message on eBay or with a phone call to 339/6645125 indicated under the advertisements. The release of negative or neutral feedback does not solve the pr.